Enhanced thermal conductivity and electrothermal conversion of epoxy composites through silane-dopamine modified graphite films

A novel surface modification technique for graphite films (GF) to improve the interface thermal resistance with epoxy resin was presented. By utilizing the self-polymerization of dopamine (PDA), dopamine micro and nanoparticles were formed on the surface of the GF. Subsequently, the surface of the epoxy resin was functionalized with polydopamine (PDA) through grafting of the silane coupling agent 3-glycidyl ether oxy-propyl trimethoxy silane (GOPTS), enabling the introduction of epoxy resin groups onto the surface of the GF. Employing a simple folding technique, a three-dimensional GF network (3DGF) was constructed, in which modified GF was successfully incorporated into the polymer matrix. The results showed that the 3DGF network further promoted the effective transfer of heat and electrons within the composite, leading to a significant improvement in thermal and electrothermal conversion performance. The prepared 3DGPGF/epoxy resin composite exhibits high thermal conductivity (7.14 W/mK) at a relatively low GF loading (31.9 wt%). Under a voltage of 12 V, the surface temperature of the sample rapidly rises from room temperature to 130°C within 200 s, and can completely melt ice cubes within 60 s. These results indicate that epoxy-silane-dopamine-modified graphite film can be a promising candidate material, and this work provides a promising strategy for designing and manufacturing high-performance composites with improved thermal properties. The developed method has the potential to be extended to other polymer matrices and fillers, and the prepared composites have enormous potential in various applications.